Flat filter for water treatment, and filter module for water treatment using same

ABSTRACT

A flat filter for water treatment is provided. The flat filter for water treatment according to one embodiment of the present invention comprises: filtration members formed in the shape of a plate having a predetermined area; support frames, which are coupled to the rim sides of the filtration members so as to support the filtration members, and have channels into/in which filtered water produced through the filtration members flows and moves; and gap adjustment members coupled to the support frames so as to adjust the gap between the filtration members adjacent to one another.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the national phase entry of InternationalApplication No. PCT/KR2016/009850, filed on Sep. 2, 2016, which is basedupon and claims priority to Korean Patent Applications 10-2015-0124486,filed on Sep. 2, 2015. The entire contents of which are incorporatedherein by reference.

TECHNICAL FIELD

The present invention relates to a flat filter for water treatment and afilter module for water treatment using the same.

BACKGROUND

The amount of wastewater discharged from domestic spaces and industrialfacilities is increasing due to rapid industrial development and urbanpopulation concentration. Accordingly, various wastewater treatmentfacilities are being developed to economically and efficiently treatwastewater.

Generally, a wastewater treatment facility is provided with a pluralityof filters, including a filtration member for filtering wastewater, andcontaminants removed from wastewater remain on the surface of thefiltration member by which wastewater is filtered.

Accordingly, to remove contaminants present on the surface of thefiltration member, a method of forcibly introducing clean water into thefilter and removing contaminants attached to the filtration member toreuse the filtration member is used.

In the case of such a contaminant removal method, to remove contaminantattached to the filtration member, it is necessary to secure a dropspace between the filters so that contaminants removed from thefiltration member can fall without hindrance.

In this regard, it is necessary that the plurality of filters areappropriately spaced apart from each other in the installation process.However, in a conventional case, since the gap between the filters isadjusted and fixed by eye by an operator during the assembly process,there may be problems, in that a gap between the filters may not beprecise and an operation time may be elongated.

In addition, in a case in which filters cannot have proper spacing byhandwork, there is a problem in that the drop space for contaminantsremoved from the filtration member may not be sufficiently secured,whereby efficient removal of contaminants may not be possible andfiltration efficiency may be decreased.

SUMMARY OF THE INVENTION

The present invention is directed to providing a flat filter for watertreatment that can easily allow a gap between adjacent filters to beadjusted in an assembly process and a filter module for water treatmentusing the same.

According to an embodiment of the present invention, there is provided aflat filter for water treatment including a plate-shaped filtrationmember having a predetermined area, a support frame coupled toperipheral portions of the filtration member to support the filtrationmember, the support frame having channels through which filtered waterproduced by the filtration member flows, and a gap adjustment membercoupled to the support frame to adjust a gap between the filtrationmember and an adjacent filtration member.

In addition, the gap adjusting member may include a water-receivingportion configured to discharge the filtered water from the channels tothe outside.

In addition, the gap adjustment member may include a body into which acorner of the support frame is inserted, and a gap adjusting portionincluding a fastening hole through which a fastening bar having apredetermined length passes.

In addition, the gap adjusting portion may include an extension plateextending from the body and having the fastening hole, and a spacingmember protruding around the fastening hole to a predetermined height toadjust the gap between the filtration member and an adjacent filtrationmember.

In addition, the support frame may include a plurality of frames coupledto the peripheral portions of the filtration member, wherein each of theplurality of frames may include a first plate, a pair of second platesextending from both ends of the first plate such that the peripheralportions of the filtration member are inserted, and stopper provided onopposite surfaces of the pair of the second plates to limit an insertiondepth by which the filtration member is inserted.

In addition, the plurality of frames may be disposed such that one endof one frame among the plurality of frames is in contact with acorresponding end of an adjacent frame among the plurality of frames,and a collection space is provided in a corner of the support frameformed by the adjacent ends, wherein flows of filtered water flowing indifferent directions through the channels join in the collection space,and the collection space may communicate with the water-receivingportion configured to discharge the filtered water to the outside.

In addition, the gap adjustment member may be coupled to a corner of thesupport frame such that both ends of a pair of adjacent frames among theplurality of frames of the support frame may be fixed.

In addition, the filtration member may include a plate-shaped firstbacking, and a nanofiber web made of nanofiber, disposed on both surfaceof the first backing.

In addition, the nanofiber web may be attached to one surface of thefirst backing by thermal fusion through a second backing.

In addition, the nanofiber web may have a melting temperature higherthan a process temperature of a thermal fusion, and the second backingmay have a lower melting temperature than the process temperature of thethermal fusion.

In addition, each of the first backing and the second backing may be awoven fabric or a nonwoven fabric, and the first backing and the secondbacking may be made of a same material.

In addition, a thickness of the second backing may be smaller than athickness of the first backing.

Meanwhile, according to another embodiment of the present invention,there is provided a filter module for water treatment including a filterassembly including a plurality of filters described above integratedthrough a fastening bar, and at least one collecting member connected inone-to-one relationship to the water-receiving portions provided in theplurality of filters to collect filtered water discharged from theplurality of filters.

In addition, the collecting member may include a main body storing thefiltered water introduced from the water-receiving portion, a pluralityof inlets configured to introduce the filtered water discharged from thewater-receiving portions into the main body, and at least one outletconfigured to discharge the filtered water from the main body to theoutside.

In addition, the collecting member may be spaced apart from thewater-receiving portions of the plurality of the filters atpredetermined gaps, and the plurality of the inlets are connected inone-to-one relationship to the respective water-receiving portionsthrough tubes.

In addition, the water-receiving portions of the plurality of thefilters may be directly inserted into the inlets of the collectingmember.

According to the present invention, the gap between adjacent filters isuniformly maintained by the gap adjustment member, thereby facilitatingassembly and increasing filtration efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view illustrating a flat filter for water treatmentaccording to an embodiment of the present invention;

FIG. 2 is an exploded view of FIG. 1;

FIG. 3 is a sectional view of a frame applied to FIG. 1;

FIG. 4 is a view illustrating a gap adjustment member applied to FIG. 1;

FIG. 5 is a view illustrating a coupling relation between the gapadjustment member and a support frame in FIG. 1;

FIG. 6 is a view illustrating a path along which filtered waterintroduces into the water-receiving portion in the flat filter for watertreatment according to the present invention;

FIG. 7 is a view illustrating another configuration of thewater-receiving portion in a flat filter for water treatment accordingto the present invention;

FIG. 8 is a view illustrating a filter module for water treatmentaccording to an embodiment of the present invention;

FIG. 9 is an enlarged view illustrating a coupling relation between thegap adjustment member and the fastening bar in FIG. 8;

FIG. 10 is a view illustrating a filter module for water treatmentaccording to another embodiment of the present invention;

FIG. 11 is a schematic view illustrating a wastewater treatment systemto which a filter module for water treatment according to the presentinvention is applied;

FIG. 12 is a view illustrating a position in which the filter module forwater treatment and a main frame applied to FIG. 11 are combined;

FIG. 13 is a view illustrating a position in which one filter moduleamong a plurality of filter modules for water treatment in FIG. 11 areseparated from the main frame; and

FIG. 14 is a view illustrating a filter module according to anotherembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the present disclosure will be described indetail with reference to the accompanying drawings so that those skilledin the art can easily carry out the present disclosure. The presentdisclosure may be embodied in various manners and is not limited to theembodiments described herein. In the drawings, parts not relating to thedescription may be omitted for clarifying the present disclosure, andthe same reference numerals may be assigned to the same or similarcomponents throughout the specification.

As illustrated in FIG. 1, a flat filter (or planar filter) 100 for watertreatment according to an embodiment of the present invention includes afiltration member 110, a support frame 120, and gap adjustment members130 and 130′.

The filtration member 110 is used to filter impurities contained inliquid to be filtered such as sewage or wastewater. The filtrationmember 110 may be a known filtration member or may be a plate-shapedmember including nanofiber webs 112 disposed on both surfaces of a firstbacking 111.

In this case, the nanofiber webs 112 serve to filter impuritiescontained in liquid to be filtered while the liquid to be filtered ispassing therethrough by suction pressure. The first backing 111 maysupport the nanofiber webs 112 and may serve as a path along which thefiltered water (or filtrate) produced by the nanofiber webs 112 flows.

In this case, the filtration member 110 may have a three-layer structurein which the nanofiber webs 112 are directly attached to both surfacesof the first backing 111, or may have a five-layer structure in whichthe nanofiber webs 112 are attached to both surfaces of the firstbacking 111 through second backings 113 as a medium (see FIG. 2).

Here, the second backings 113 may have a thickness smaller than thethickness of the first backing 111 so as to reduce the overall thicknessof the filtration member 110 and may be layered on one surface of thefirst backing 111.

Consequently, the nanofiber webs 112 are attached to the first backing111 through the second backings 113, instead of being directly providedon the first backing 111, thereby improving adhesion and facilitatingattachment.

For example, the nanofiber webs 112 may be attached to the first backing311 through the second backings 113 by thermal fusion, ultrasonicfusion, high frequency fusion, or the like.

Here, the second backings 113 may be partially or completely melted andattached to the first backing 111 in the attachment process.

In this case, the nanofiber webs 112 may have a melting temperaturehigher than the process temperature of the fusing process so as not tobe melted by heat, and the second backings 113 may have a meltingtemperature lower than the process temperature of the fusion process.

Accordingly, the filtration member 110 may be embodied as a three-layerstructure in which the second backings 113 are completely melted, or maybe embodied as a five-layer structure in which only portions of thesecond backings 113 are melted and the other portions of the secondbackings 113 remain between the nanofiber webs 112 and the first backing111. However, the structure of the filtration member 110 is not limitedthereto. It should be appreciated that one or more backings may beinterposed between the two nanofiber webs 112.

In addition, the first backing 111 and the second backings 113 may beporous base materials to serve as paths through which the filtered waterproduced by the nanofiber webs 112 flows.

For example, the first backing 111 and/or the second backings 113 may beany one of commonly known woven fabric, knitted fabric, and nonwovenfabric, which are used conventionally. Here, the woven fabric means thatthe fibers included in the fabric are oriented in longitudinal andtransverse directions, and the specific structure may be plain weave,twill weave, and the like, and the density of warp and weft yarn is notparticularly limited. In addition, the knitted fabric may have a knownknit structure, and may be weave knitted fabric, light knitted fabric,or the like. However, the knitted fabric is not particularly limitedthereto. The nonwoven fabric may be known nonwoven fabric, selected fromamong dry nonwoven fabric, such as chemical bonding nonwoven fabric,thermal bonding nonwoven fabric, airlaid nonwoven fabric; a wet nonwovenfabric; spunlace nonwoven fabric, needle punched nonwoven fabric, ormeltblown nonwoven fabric. The pore size, porosity, and basis weight ofthe nonwoven fabric may vary depending on intended levels of waterpermeability, filtration efficiency, and mechanical strength.

In other words, the materials of the first backing 111 and/or the secondbackings 113 are not limited. For example, synthetic fiber selected fromthe group consisting of polyester, polypropylene, nylon and polyethyleneor natural fiber including a cellulose-based material may be used.

However, to prevent separation between the first backing 111 and/or thesecond backings 113 and the nanofiber webs 112 during the watertreatment process by improving the binding force with the nanofiber webs112 and to prevent problems, such as lowered water permeability due touse of a separate adhesive component, the first backing 111 and thesecond backings 113 may include a low-melting-point polymer compound,such as low-melting-point polyester or low-melting-point polyethylenecapable of thermal fusion, or may be polyester-based low-melting-pointconjugated fiber including low-melting-point polyester as a sheath andpolyethylene terephthalate as a core and/or polyolefin-basedlow-melting-point conjugated fiber including low-melting-pointpolyethylene as a sheath and polypropylene as a core.

Here, the melting point of the low-melting-point polymer compound may be60 to 180° C., and the thickness of the first backing 111 may be 2 to200 μm, but the present disclosure is not limited thereto.

Meanwhile, the second backings 113, applied to the present invention,may be made of a material different from that of the first backing 111,but may be made of the same material as the first backing 111 toincrease the adhesion with the first backing 111 in the laminatingprocess.

The nanofiber webs 112 are configured to filter impurities contained inliquid to be filtered, and may be made of nanofibers. In this case, thenanofibers may include a fiber forming component, includingpolyacrylonitrile (PAN) and polyvinylidene fluoride (PVDF), and anemulsifying agent for improving the miscibility of the fiber formingcomponent.

Here, the fiber forming component may include polyacrylonitrile (PAN,hereinafter referred to as PAN) having high hydrophilicity andpolyvinylidene fluoride (PVDF, hereinafter referred to as PVDF) havinghigh hydrophobicity.

The PVDF can guarantee the mechanical strength and chemical resistanceof the nanofibers due to the nature of the material. Since the PAN ishydrophilic, hydrophobicity of the nanofibers due to the PVDF isprevented and hydrophilicity of the nanofibers is improved, thereby thePAN allows enhanced water permeability to be expressed when thenanofibers are attached to the filtration member.

In addition, the nanofiber webs 112 may include nanofiber webs having athree-dimensional network structure. For example, nanofibers including afiber-forming component, including polyacrylonitrile (PAN) andpolyvinylidene fluoride (PVDF), as well as an emulsifying agent, arelaminated perpendicularly to the radiation surface. This canconsequently cause fusion at the contacting portions between thelaminated nanofibers due to a solvent, which is notvolatilized/evaporated in the air during spinning, thereby forming athree-dimensional network structure.

Such the nanofiber webs 112 may be provided as a single layer or may beprovided multiple layers.

The support frame 120 may be disposed on the peripheries of thefiltration member 110 to support the peripheries of the filtrationmember 110, such that the filtration member 110 maintains a plate shape.

Although the support frame 120 may be embodied as a single member tototally and partially support the peripheries of the filtration member110, the support frame 120 may include a plurality of frames 120 a and120 b coupled to the peripheries of the filtration member 110.

For example, the plurality of frames 120 a and 120 b may be disposed onthe peripheries of the filtration member 110, respectively, such thatone end portion of one frame among the plurality of frames 120 a and 120b contacts a corresponding end portion of the other frame of theplurality of frames 120 a and 120 b. The end portions of two adjacentframes among the plurality of 120 a and 120 b may be connected to eachother through gap adjustment members 130 and 130′ disposed on corners ofthe filtration member 110.

However, the shape of the support frame is not limited thereto. Theshape of the support frame may be changed to a variety of shapes, suchas a circle, an arc, a polygon, or combinations thereof, according tothe shape of the filtration member 110. The support frame may have anyshape as long as the support frame covers the entirety of theperipheries of the filtration member.

In this case, the support frame 120 may serve to support the filtrationmember 110 while serving as a flow path through which the filtered waterproduced by the filtration member 110 flows to the water-receivingportion 133 due to suction force applied from the outside.

In this regard, each of the frames 120 a and 120 b of the support frame120 may provided substantially in the shape of a latter ‘C’ or ‘U’, withone side thereof being open, and a flow path 125 through which thefiltered water introduced from the filtration member 110 flows may beprovided in the interior thereof (see FIG. 3).

Specifically, the plurality of frames 120 a and 120 b may include afirst plate 121 having the shape of a plate and a pair of second plates122 and 123 extending perpendicularly from both end portions of thefirst plate 121.

Thus, the filtration member 110 may be supported by the pair of secondplates 122 and 123 which face each other, with a periphery of thefiltration member 110 being inserted into a space defined between thepair of second plates 122 and 123. In this case, the periphery of thefiltration member 110 may be inserted into the space, defined betweenthe pair of second plates 122 and 123, to be spaced apart by apredetermined distance from the first plate 121.

That is, a stopper 125 for limiting an insertion depth by which thefiltration member 110 is inserted may be provided on the oppositesurfaces of the pair of second plates 122 and 123 facing each other (seeFIG. 3).

Thus, since the insertion depth of the filtration member 110 is limitedby the stopper 125 in the process of fastening the periphery of thefiltration member 110 to the each of the frames 120 a and 120 b, apredetermined space may be formed between the periphery of thefiltration member 110 and the first plate 121 (see FIG. 6).

Accordingly, when the filtration member 110 and the frames 120 a and 120b are coupled, the periphery of the filtration member 110 is alwaysmaintained to be spaced apart from the first plate 121, thereby forminga channel 124 along which fluid, such as filtered water or washingwater, can flow.

In the present invention, the stopper 125 may be formed on each ofopposite surfaces of the pair of second plates 122 and 123 facing eachother, but may be formed only on the inner surface of any one of thepair of second plates 122 and 123. In addition, the stopper 125 may betotally or partially provided with respect to the longitudinal directionof each frame. In a case in which the stopper 125 are formed on theopposite surfaces of the pair of second plates 122 and 123 facing eachother, the respective stopper 125 are spaced apart from each other at apredetermined gap, thereby filtered water can flow toward the channel124 through the gap.

The gap adjusting members 130 and 130′ are coupled to the corners of thesupport frame 120 both to fasten the two adjacent frames 120 a and 120 band to adjust the gap between the adjacent filtration members 110.

The gap adjustment members 130 and 130′ may be provided as a pluralityof gap adjustment members. The gap adjustment members 130 and 130′ maybe coupled to the corners of the support frame 120 and to fix the endportions of two adjacent frames 120 a and 120 b.

In this regard, the gap adjustment members 130 and 130′ may include abody 131 having one open portion, allowing one end portion of anadjacent frame 120 a or 120 b to be fitted thereinto.

Accordingly, two adjacent frames among the plurality of frames 120 a and120 b of the support frame 120 may be fixed by the body 131, with endportions thereof being inserted into the body 131.

For example, the end portion of one frame of the two adjacent frames 120a and 120 b may be inserted in a first direction of the body 131, whilethe end portion of the other frame 120 b may be inserted in a seconddirection of the body 131 to be disposed in contact with the end portionof the frame 120 a inserted in the first direction (see FIGS. 5 and 6).

In this case, since a channel 124 formed in the frame 120 a inserted inthe first direction and a channel 124 formed in the frame 120 b insertedin the second direction are disposed to communicate with each other, allof the channels formed in the plurality of the frames 120 a and 120 bmay communicate with each other.

Here, the first direction and the second direction may be orthogonal toeach other on the same plane or may be inclined to each other to form apredetermined angle with respect to one straight line on the same plane.

Meanwhile, in a case in which a plurality of flat filters 100 for watertreatment according to the present invention are arranged in parallel toeach other, the flat filter 100 may include a gap adjusting portion 132so that the respective filtration members 110 may be spaced apart fromeach other.

The gap adjusting portion 132 may be provided on at least one frameamong the plurality of frames 120 a and 120 b of the support frame 120.Preferably, the gap adjusting portion 132 may be provided on at leastone of the gap adjusting members 130 and 130′.

For example, the gap adjusting portion 132 may include an extensionplate 132 a, having a fastening hole 132 b formed therein, and a spacingmember 132 c. The gap adjusting portion 132 may be provided on one sideof the gap adjustment member 130 or 130′ (see FIGS. 4 and 5).

Specifically, the extension plate 132 a may extend outward from the body131 of the gap adjustment member 130 or 130′, and may have the fasteninghole 132 b through which a fastening bar 240 passes (see FIG. 4).

Here, the fastening hole 132 b are illustrated as being formed in theextension plate 132 a in a circular shape, but the shape of thefastening hole 132 b is not limited thereto, and may have a shapecorresponding to the cross-sectional shape of the fastening bar 240. Forexample, the cross-sectional shape of the fastening hole 132 b may beone selected from among a circle, an arc, a polygon, and combinationsthereof.

In this case, the spacing member 132 c may protrude from the one surfaceof the extension plate 132 a to a predetermined height so as to have apredetermined thickness. The spacing member 132 c may be provided tosurround the entirety or a portion of the periphery of the fasteninghole 132 b.

Here, the spacing members 132 c may be formed on both sides of theextension plate 132 a, respectively or may be formed on only one side ofthe extension plate 132 a. In addition, the spacing member 132 c may beformed as a multi-step structure including a plurality of steppedportions extending to different heights from one surface of theextension plate 132 a.

Here, a plurality of filtration members 110 may be arranged in parallelto each other to have a gap of 3 mm or more, but are not limitedthereto. In addition, the plurality of filtration members 110 may bedisposed to have various gaps by suitably changing the height orthickness of the spacing members 132 c.

Thus, in a case in which the plurality of the flat filter 100 for watertreatment according to the invention are connected to each other throughthe fastening bars 240, the plurality of filtration members 110 disposedparallel to each other may be spaced apart from each other through thespacing members 132 c even if the respective flat filters 100 arecompletely in contact with each other (see FIG. 9).

Accordingly, when the plurality of the flat filters 100 for watertreatment are disposed in parallel, the fastening bars 240 are fastenedto pass through the fastening holes 132 b, respectively, and then theflat filters 100 are brought into close contact with each other, theadjacent filtration members 110 may be spaced apart from each other atpredetermined gaps through the spacing members 132 c.

That is, in a case in which a flat filter module 200 is configured usinga plurality of flat filters 100 for water treatment, when the flatfilters 100 connected to the fastening bar 240 are brought into closecontact with each other, uniform gaps may be formed between the adjacentfiltration members 110 by the spacing members 132 c, even if an operatordoes not adjust the gaps between the flat filters, respectively. Inaddition, when fixing members, such as nuts, are fastened to both endsof the fastening bar 240, the gaps between the filtration members 110may be maintained.

Accordingly, since liquid to be filtered may be present on both sides ofeach of the filtration members 110, liquid to be filtered can flow fromboth sides of the filtration member 110 to the inside of the filtrationmember 110 due to suction force provided from the outside, therebyproducing filtered water.

In addition, in a case in which a back-washing operation is performed toremove impurities adhered to the filtration member 110 after therepetitive production operations of the filtered water have beenperformed, the impurities adhered to the filtration member 110 may beseparated by the pressure of fluid, such as washing water, supplied fromthe outside, thereby falling into a space between the adjacentfiltration members 110.

Meanwhile, at least one of the gap adjustment members 130 may include anwater-receiving portion 133 to discharged the filtered water flowingalong the channel 124 formed in each of the frames 120 a and 120 b tothe outside (see FIG. 4).

That is, in the plurality of gap adjustment members 130 and 130′ coupledto the corners of the supporting frame 120, each gap adjustment member130′ without the water-receiving portion 133 may only serve to connect apair of adjacent frames, while each gap adjustment member 130 includingthe water-receiving portion 133 may serve to connect a pair of adjacentframes and also serve as an outlet for discharging filtered water to theoutside through the water-receiving portion 133.

The water-receiving portions 133 may be connected to a collecting member230, which will be described later.

Here, although the water-receiving portion 133 may be provided only inone gap adjustment member among the plurality of gap adjustment members,it is preferable that the water-receiving portion 133 be provided oneach of the two gap adjustment members 130 to provide uniform suctionpressure toward the filtration member 110.

In addition, although the water-receiving portion 133 may be formedintegrally with the body 131 of the gap adjustment member 130 (see FIG.4), a coupling hole 135′ may be formed in the body 131′ and anwater-receiving portion 133′ having a predetermined length may bedetachably coupled to the coupling hole 135′. That is, as illustrated inFIG. 7, the water-receiving portion 133′ may be provided as a hollowmember having a predetermined length and may be screwed or fitted into acoupling hole 135′ formed in the body 131′. Accordingly, when thewater-receiving portion 133′ is required to be changed or replacedduring use, only the water-receiving portion 133′ may be easily removedto be replaced or changed by a new one.

In this case, when the gap adjustment member 130 including thewater-receiving portion 133 is coupled to two adjacent frames 120 a and120 b, the gap adjustment member 130 may be provided with a collectionspace 134 communicating with the channels 124 formed in the two frames120 a and 120 b, the collection space 134 may be provided in a positioncommunicating with the water-receiving portion 133.

For example, the collection space 134 may be formed in the end portionsof the two frames 120 a and 120 b, which are inserted into the gapadjustment member 130 when the gap adjustment member 130 having thewater-receiving portion 133 is coupled to the two frames 120 a and 120b. The collection space 134 may also be formed by cutting the endportion of one of the two frames 120 a and 120 b inserted into the gapadjustment member 130 (see FIG. 5) so that the shapes of the endportions of the frames 120 a and 120 b do not conform to each other.

Accordingly, filtered water flowing along channel 124 formed in oneframe 120 a of the frames 120 a and 120 b and filtered water flowingalong the channel 124 formed in another frame 120 b thereof may joineach other in the collection space 134, and may be discharged to theoutside through the water-receiving portion 133 communicating with thecollection space 134 (see FIG. 6).

As a result, the filtered water produced in a process of flowing fromthe outside to the inside of the filtration member 110 by suction forceprovided from a pump 320 may flow into the channels 124 of the pluralityof frames 120 a and 120 b, and may be discharged to the outside throughthe water-receiving portion 133 after the filtered water flows towardthe collection space 134 along the channels 124.

In contrast, in the back-washing operation, a fluid, such as washingwater, supplied from the outside may pass through the collection space134 after the fluid is introduced inside through the water-receivingportion 133, and then may flow into the channels 124 formed in theplurality of frames 120 a and 120 b.

Meanwhile, a plurality of flat filters 100 for water treatment, asdescribed above, may be arranged in parallel to each other and be fixedto each other through the fastening bars 240, thereby modularizing intoa single filter module 200 for water treatment.

For example, as illustrated in FIG. 8, the filter module 200 for watertreatment may include a filter assembly 210, a fixing frame 220, and acollecting member 230.

The filter assembly 210 may include a plurality of flat filters 100 forwater treatment as described above. In addition, the filter assembly 210may be a form integrated through the fastening bar 240 having apredetermined length in state in which the plurality of flat filters 100are arranged in parallel to each other.

Here, the plurality of flat filters 100 may for water treatment mayinclude a filtration member 110, a support frame 120, and gap adjustmentmembers 130 and 130′. In this embodiment, since the filtration member110, the support frame 120, and the gap adjustment members 130 and 130′are the same as those described above, detailed descriptions thereofwill be omitted.

In this case, in the filter assembly 210, the adjacent filtrationmembers 110 may be spaced apart from each other through the spacingmembers 132 c thereof such that a predetermined space is formed betweenthe filtration members 110 facing each other.

Specifically, as illustrated in FIG. 9, when one filter 100 b(hereinafter referred to as a “second filter”) of the plurality offilters arranged in parallel is brought into close contact with the rearsurface of another filter 100 a (hereinafter referred to as a “firstfilter”), the spacing members 132 c of the gap adjustment members 130and 130′ provided in the first filter 100 a and the spacing members 132c of gap adjustment members 130 and 130′ provided in the second filter100 b are in contact with each other.

Accordingly, a predetermined space may be formed between the filtrationmember 110 of the first filter 100 a and the filtration member 110 ofthe second filter 100 b by pairs of spacing members 132 c, which are incontact with each other. That is, when the plurality of filters 100 arefastened to the fastening bars 240 such that the filters 100 are inclose contact with each other, predetermined gaps may be formed betweenthe filters 100 arranged adjacent to each other by the spacing members132 c in the process in which the filters 100 are fit together throughthe fastening bars 240.

This can consequently eliminate the inconvenience that the operator hasto adjust the gaps between the filters 100 one by one. In addition, in acase in that the plurality of filters are brought into close contactwith each other, the gaps between the filters may be formed to beuniform since the gaps between the filters are formed by the spacingmembers 132 c.

In addition, when the fixing members 242 such as a nut are fastened toboth sides of the fastening bars 240, the gaps formed between therespective filters may be maintained to be uniform.

The fixing frame 220 may be coupled to both end portions of thefastening bars 240 such that it is integrated with the filter assembly210.

The fixing frame 220 may be embodied as a plate-shaped member, but maybe provided as a frame structure allowing liquid to be filtered to flowinto the filter assembly 210.

For example, the fixing frame 220 may include a front frame 221 and arear frame 222 disposed on the front and rear surfaces of the filterassembly 210, respectively. In addition, both end portions of thefastening bars 240 may be coupled to the front frame 221 and the rearframe 222, respectively. Accordingly, the filter assembly 210 and thefixing frame 220 may be integrated through the fastening bars 240.

Here, the front frame 221 and the rear frame 221 may include fasteningholes (not shown), into which the end portions of the fastening bars 240are inserted in the fitting manner, or may include through-holes (notshown), through which the fastening bars 240 passes, with both endportions thereof being fixed using separate fixing members.

In this case, a handle 223 may be provided on a portion of the fixingframe 220 such that the user or operator may easily hold the modularizedflat filter module 200.

Further, each of the members constituting the front frame 221 and therear frame 221 may be a plate-shaped bar having a predetermined widthand length, may be an I-beam or an L-beam, or may be provided as a pipehaving a polygonal cross-section.

As described above, in the filter module 200 for water treatmentaccording to the present invention, the plurality of flat filters 100may be arranged in parallel to each other, and the filtration members110 of the respective flat filters 100 may be arranged in a state inwhich the filtration members 110 are spaced apart from each other atpredetermined gaps through the spacing members 134 c.

Accordingly, suction force provided from the outside, for example,suction force provided from one pump 320 may be transmitted to aplurality of flat filters 100 through the respective water-receivingportions 133 such that each of the plurality of flat filters 100 mayproduce filtered water in a single process.

Consequently, it is possible to simultaneously produce a large amount offiltered water using the plurality of flat filters 100, therebyimproving the production efficiency of the filtered water.

The collecting member 230 serves to transmit suction force to each ofthe filters so that filtered water can be simultaneously produced by thefilters in a single suction process and also serves to collect filteredwater produced by the filters.

That is, since the collecting member 230 is connected to thewater-receiving portion 133 of each of the filters 100, suction forceprovided from the outside may be simultaneously transmitted to therespective filters, and filtered water may be separately produced by thefilters 100 using the suction force transmitted thereto. Then, filteredwater produced by the filters 100 may be introduced into the collectingmember 230 via the collection space 134 and the water-receiving portion133 by suction force, thereby being integrated.

In addition, the collecting member 230 may distribute high-pressurefluid, such as washing water or high-pressure air supplied from theoutside to the respective filters 100 during the back-washing process.

The collecting member 230 may be provided as a single member.Alternatively, in a case in which each of the filters includes aplurality of water-receiving portions 133, the collecting member 230 maybe provided in an appropriate number corresponding to the number of thewater-receiving portions 133 and may be connected in one-to-onerelationship to each of the water-receiving portions 133.

For example, as illustrated in FIG. 8, when two water-receiving portions133 are provided on the upper portion and the lower portion of each ofthe filters 100, two collecting member 230 may also be provided. Inaddition, one of the two collecting members 230 may be connected to thewater-receiving portion 133 located on the upper portion and the othercollecting member 230 may be connected to the water-receiving portion133 located on the lower portion.

The collecting member 230 may include a main body 231 having a storagespace 234 in which filtered water introduced from the water-receivingportions 133 is temporarily collected, inlets 232 for introducing thefiltered water discharged from the water-receiving portion 133 into thestorage space 234 and outlets 233 for discharging filtered waterintroduced from the storage space 234 to the outside (for example, afiltered water storage tank 350) or providing suction force suppliedfrom the outside to the water-receiving portion 133.

Here, in a back-washing process for removing impurities adhered to thefiltration member 110, the inlets 232 may serve as outlets for supplyinghigh-pressure fluid to the filter 100, and the outlets 233 may serve asinlets for introducing the high-pressure fluid supplied from the outsideinto the collecting member 230.

In this case, a plurality of inlets 232 may be provided to be connectedto the water-receiving portions 133 of the filters 100, respectively. Inaddition, the inlets 232 and the receiving port 133 may be connected toeach other in one-to-one relationship.

For example, as illustrated in FIG. 8, the plurality of inlets 232 maybe connected in one-to-one relationship to the water-receiving portions133 through tubes 240. As illustrated in FIG. 10, the water-receivingportions 133 may be directly connected to the inlets 232′ of thecollecting member 230′.

Here, in a case in which the water-receiving portions 133 are directlyconnected to the inlets 232′ of the collecting member 230, the inlets232′ may be formed into holes on a surface of the main body 231′ havinga storage space 234 in which filtered water introduced from thewater-receiving portions 133 is temporarily collected, such thatwater-receiving portions 133 protruding by a predetermined length aredirectly inserted into the inlets 232′. In this case, a sealing member(not shown) may be provided on contact surfaces of the inlets 232′ andthe water-receiving portions 133 to prevent filtered water from leaking.

Meanwhile, in a case in which the inlets 232 and the water-receivingportions 133 are connected through the tubes 240, the collecting member230 may be disposed at a middle portion of the fixing frame 220 so as tobe spaced apart from the water-receiving portions 133 to a predetermineddistance.

This is because, if the gap between the water-receiving portions 133 andthe inlets 232 is too narrow, the tube 240 may be bent during aconnection process, thereby preventing filtered water from smoothlyflowing.

Like this, in the filter module 200 for water treatment according to thepresent invention, since the collecting member 230 is connected to thewater-receiving portions 133 of the filters 100, filtered water may beproduced simultaneously by the filters in a single suction process, anda back-washing process for removing impurities adhered to the filtrationmembers 110 may also be performed simultaneously. In addition, since theplurality of filters 100 spaced apart from each other at appropriategaps through the gap adjustment members 130 and 130′ are integrated as asingle module, the filter module 200 may be easily installed and may beeasily replaced as a module, thereby advantageously facilitatingmaintenance.

The above-described filter module 200 for water treatment may be appliedto a wastewater treatment system 300. For example, as illustrated inFIG. 11, the wastewater treatment system 300 may include at least onefilter module 200, a main frame, and a pump 320.

The filter module 200 is intended to produce filtered water by filters100 using suction force provided by the pump 320. The filter module 200may include a filter assembly 210 that a plurality of filters 100 arecoupled to each other through fastening bars 240, a fixing frame 220,and a collecting member 230.

The filter module 200 may be provided as a single module, but may beprovided in a plurality of filter modules. In addition, the plurality offilter modules may be supported by the main frame.

Here, the filter assembly 210, the fixing frame 220, and the collectingmember 230, which are components of the filter module 200, are the sameas those described above, and detailed descriptions thereof will beomitted.

The main frame is intended to support the filter module 200, and may beembodied as a hollow frame structure having a main channel therein.

The main frame may include an upper main frame 311 disposed above thefilter module 200 and a lower main frame 311 disposed below the filtermodule 200 to firmly support the filter module 200, in which the uppermain frame 311 and the lower main frame 312 may be connected to eachother through a plurality of support bars.

Thus, the main frame may form a space for accommodating at least onefilter module 200 therein.

In this case, at least one of the upper main frame 311 and the lowermain frame 312 may be provided with guide rails 314 guiding slidingmovements of the filter module 200 by supporting the edges of the filtermodule 200 during insertion of the filter module 200 (see FIG. 13).

For example, each of the guide rails 314 may be provided assubstantially L-shaped angle bars and may be disposed in the samedirection as the direction in which the filter module 200 is inserted.Accordingly, when the filter module 200 is inserted, the filter module200 may be smoothly slid, since the edges thereof are supported.

Preferably, the guide rails 314 may be provided on both the upper mainframe 311 and the lower main frame 312 to simultaneously support theupper edges and the lower edges of the filter module 200.

Meanwhile, at least one of the upper main frame 311 and the lower mainframe 312 may include a main channel 315 formed therein to collectfiltered water introduced from the filter modules 200.

For example, the main channel 315 may be formed in any one of aplurality of members of the lower main frame 312. In addition, the lowermain frame 312 may be provided with a plurality of fittings 316 a and316 b communicating with the main channel 315.

Here, the plurality of fittings 316 a and 316 b serve as inlets andoutlets for the inflow or outflow of filtered water, some fittings 316 aamong the plurality of fittings 316 a and 316 b may be connected to theoutlets 233 of the collecting member 230 through connection pipes 371.In this case, the connection pipes 371 may be implemented as rigidtubular members or may be implemented as known pipes made of a flexiblerubber material.

In addition, the remaining fittings 316 b among the plurality offittings 316 a and 316 b may be connected to a filtered water storagetank 330, allowing filtered water, produced by the filters using suctionforce provided by the pump 320, to flow into the filtered water storagetank 330.

Here, when a single filter module 200 is provided, the main frame 310may be omitted. In this case, the outlets 233 of the collecting member230 may be directly connected to the filtered water storage tank 350.

The pump 320 is connected to at least one of the fittings 316 b amongthe fittings 316 a and 316 b of the main frame 310 and may providesuction force to produce filtered water by the filters 100 provided inthe filter modules 200.

That is, suction force provided by the pump 320 may be transmitted tothe filtration member 110 through the main channel 215, the collectingmember 230, the water-receiving portions 133, and then the channels 124formed in the plurality of frames 120 a and 120 b of the support frame.Accordingly, liquid to be filtered, such as sewage or wastewater,existing around the filters 100 may flow toward the filtration members110 by suction force, thereby being filtered through the nanofiber webs112. And then, filtered water flown to the first backing layers 111through the nanofiber webs 112, may be introduced into the channels 124of the support frame by suction force and, may flow toward thecollection spaces 134. Thereafter, filtered water may flow to collectingmember 230 through the water-receiving portions 133 and may becollected. After collected in the collecting member 230, filtered watermay flow along the main channel 315 of the main frame to be stored inthe filtered water storage tank 330.

Accordingly, the wastewater treatment system 300 according to thepresent invention may produce a large amount of filtered water because aplurality of filters can be operated simultaneously by suction forceprovided by the pump 320.

Meanwhile, in the case in which contaminants are adhered to the surfacesof the filtration members 110, more specifically, the surfaces of thenanofiber webs 112 due to repetitive filtration operations, thewastewater treatment system 300 may supply fluid, such as washing wateror air, to the respective filters 100 using the pump 320 to remove, thecontaminants from the surfaces of the nanofiber webs 112. As a result,the contaminants adhered to the surface of the filtration member 110 maybe desorbed by the supply pressure of fluid.

For example, at least some the fittings 316 b among the plurality offittings 316 a and 316 b may be connected to a washing water storagetank 340 in which washing water is stored. Here, the fittings 316 bconnected to the washing water storage tank 340 may be fittings 316 bconnected to the filtered water storage tank 330, and a channel controlvalve 350 may be provided on the connection pipe 360, therebycontrolling the connection pipe 360 to be selectively connected to ordisconnected from the filtered water storage tank 330 and the washingwater storage tank 340.

Accordingly, when the filtration member 110 needs to be cleaned, washingwater stored in the washing water storage tank 340, may be supplied tothe respective filters 100 by the pump 320. As a result, contaminantsadhered on the filtration member 110 may be removed by the pressure ofthe washing water.

Specifically, washing water, stored in the washing water storage tank340, may be supplied to the respective filters 100 by the pump 320 at apredetermined pressure. In this case, two water-receiving portions 133may be provided on each of the filters 100, such that washing water maybe uniformly and totally introduced into the filtration members 110 byflowing in both directions along the channels 125 formed in the supportframe 120. Accordingly, washing water, supplied to the channel sides ofthe support frame through the water-receiving portion 133, may flow tothe filtering member 110 and may desorb the contaminants remaining onthe surface of the filtering member 110 by supply the pressure thereof,thereby removing the contaminants from the surfaces of the filtrationmembers 110. Here, the contaminants desorbed from the filtration member110 may fall through the spaces formed between the filters by thespacing members 132 c.

Meanwhile, a filter module 400 for water treatment according to anotherembodiment of the present invention is illustrated in FIG. 14. That is,the filter module 400 for water treatment may include fitting members430 as a means for adjusting gaps between adjacent filters among aplurality of filters 100′.

That is, the filter module 400 for water treatment may include aplurality of flat filters 210′ for water treatment, a fixing frame, acollecting member 230, and the fitting members 440.

In the present embodiment, each of the pi y of filters 100′ may includea support frame including the above-described filtration member 110 anda plurality of frames 120 b, and may be configured to connect adjacentend portions of the frames 120 b using separate connection members 140.In addition, the fitting member 430 may substitute for the function ofthe gap adjusting portion (132 in FIG. 1) for adjusting the gaps betweenthe adjacent filters 100.

In addition, the filter 100′ may include the same components as those ofthe filter 100 illustrated in FIG. 1, except for the gap adjustingportion 132. Although the water-receiving portion 133 formed in each ofthe filters may be provided in the connection member 140, thewater-receiving portion 133 may be provided in the middle of the lengthof the frame 120 b of the support frame so as to communicate with thechannel 124 formed in the frame.

In this case, the connection members 140 coupled to the corners of thesupport frame merely serve to connect the end portions of the adjacentframes 120 b to each other. The remaining components are the same, anddetailed descriptions thereof will be omitted.

For example, the filter module 400 for water treatment according to thepresent embodiment may be configured such that the water-receivingportions 133 are provided in middle portions of the length of each ofthe frames 120 b of the support frames, the filters 100′ are spacedapart from each other at predetermined gaps through the fitting member430, and the water-receiving portions 133 of the filters 100′ areconnected in one-to-one relationship to the inlets 232 of the collectingmember 230 through the tubes 240.

Here, the collecting member 230 may include a main body 231 having astorage space 234 in which filtered water introduced from thewater-receiving portions 133 is temporarily stored, inlets 232 forintroducing filtered water discharged from the water-receiving portions133 into the storage space 234, outlets 233 for discharging filteredwater from the storage space 234 to the outside (for example, thefiltered water storage tank 350) or providing suction force suppliedfrom the outside to the water-receiving portions 133. Since details ofthe collecting member 230 are the same as those described above,detailed descriptions thereof will be omitted.

The fitting members 430 are intended to adjust the gap between theplurality of filters.

Each of the fitting members 430 may include a connection bar 431 and aplurality of support pieces 432. In this case, both end portions of theconnection bar 431 may be in contact with the pair of frames 221 and 222of the fixing frame. In addition, the plurality of support pieces 432may be disposed on one surface of the connection bar 431 in thelongitudinal direction to be spaced apart from each other atpredetermined gaps, and may protrude from the connection bar 431 in thesame direction to each other. Accordingly, fitting recesses 433 may beformed between adjacent support pieces 432, such that the filters 100′may be inserted into the fitting recesses 433. Here, the gaps betweenadjacent support pieces 432 may be formed to be substantially equal tothe thicknesses of the filters 100′, more specifically, the thicknessesof the frames 120 b.

In this case, the plurality of support pieces 432 may be disposed on onesurface of the connection bar 431 to be spaced apart from each other atregular gaps along the longitudinal direction. Accordingly, when therespective filters 100′ are inserted into the fitting recesses 433, theplurality of filters 100′ arranged in parallel to each other may bespaced apart from each other at equal gaps.

Here, both end portions of the fitting members 430 may be fixed to or insimple contact with the fixing frame 410. In addition, a single fittingmember or a plurality of the fitting members 430 may be used.

The filter module 400 may also be applied in place of theabove-described filter module of the wastewater treatment system. Inthis case, process of producing filtered water by providing suctionforce using the pump and the process of removing contaminants adhered tothe filtration member are the same as above, detailed descriptionsthereof will be omitted.

Although exemplary embodiments of the present disclosure have beendescribed, the exemplary embodiments described in the specification areintended to not limit the technical spirit of the present disclosure,and a person having ordinary skill in the art who understands the spiritof the present disclosure should appreciate that another embodiment maybe easily suggested by additions, modifications, deletions, supplements,and the like, made within the scope of the same spirit, and the otherembodiments may also be included within the scope and sprit of thepresent disclosure.

What is claimed is:
 1. A flat filter for water treatment, comprising: aplate-shaped filtration member having a predetermined area; a supportframe coupled to peripheral portions of the filtration member to supportthe filtration member, the support frame having channels through whichfiltered water produced by the filtration member flows; and a gapadjustment member coupled to the support frame so as to space thefiltration member and an adjacent filtration member from each other, thegap adjustment member including a body into which a corner of thesupport frame is inserted, and a gap adjusting portion including afastening hole through which a fastening bar having a predeterminedlength passes, wherein the support frame comprises a plurality of framescoupled to the peripheral portions of the filtration member, and whereineach of the plurality of frames includes a first plate, a pair of secondplates extending from both ends of the first plate such that theperipheral portions of the filtration member are inserted, and a stopperprovided on opposite surfaces of the pair of the second plates to limitan insertion depth by which the filtration member is inserted.
 2. Theflat filter of claim 1, wherein the gap adjustment member includes awater-receiving portion configured to discharge the filtered waterintroduced from the channels to the outside.
 3. The flat filter of claim1, wherein the gap adjusting portion includes: an extension plateextending from the body, and having the fastening hole; and a spacingmember protruding at a predetermined height around the fastening hole soas to space the filtration member and an adjacent filtration member fromeach other.
 4. The flat filter of claim 2, wherein the plurality offrames are disposed such that one end of one frame among the pluralityof frames is in contact with a corresponding end of an adjacent frameamong the plurality of frames, and a collection space is provided in acorner of the support frame formed by the adjacent ends, wherein flowsof filtered water flowing in different directions through the channelsjoin in the collection space, and the collection space communicates withthe water-receiving portion configured to discharge the filtered waterto the outside.
 5. The flat filter of claim 1, wherein the gapadjustment member is coupled to a corner of the support frame such thatboth ends of a pair of adjacent frames among the plurality of frames ofthe support frame is fixed.
 6. The flat filter of claim 1, wherein thefiltration member includes: a plate-shape first backing; and a nanofiberweb made of nanofiber, disposed on the first backing.
 7. The flat filterof claim 6, wherein the nanofiber web is attached to one surface of thefirst backing by thermal fusion through a second backing.
 8. The flatfilter of claim 7, wherein the nanofiber web has a melting temperaturehigher than a process temperature of a thermal fusion, and the secondbacking has a lower melting temperature than the process temperature ofthe thermal fusion.
 9. The flat filter of claim 7, wherein each of thefirst backing and the second backing is a woven fabric or a nonwovenfabric.
 10. The flat filter of claim 7, wherein the first backing andthe second backing are made of a same material.
 11. The flat filter ofclaim 7, wherein a thickness of the second backing is smaller than athickness of the first backing.